What type of algorithm uses the same key to encrypt and decrypt data?

What type of algorithm uses the same key to encrypt and decrypt data?
A . a symmetric algorithm
B . an asymmetric algorithm
C . a Public Key Infrastructure algorithm
D . an IP security algorithm

Answer: A

Explanation:

A symmetric encryption algorithm, also known as a symmetrical cipher, uses the same key to encrypt the data and decrypt the data.

Source: Cisco Official Certification Guide, p.93